Erosion control substrate and methods of use

ABSTRACT

A substrate and a slurry for erosion control and/or hydroseeding are disclosed. The substrate includes mulch and a cover composition including bentonite clay and cellulosic water dispersible polymer or starch. Other desired optional ingredients may also be included. Methods of controlling or reducing erosion control are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/195,033, filed on Jun. 28, 2016, which is a continuation of U.S.application Ser. No. 14/179,641, filed on Feb. 13, 2014. The entiredisclosures of each of the prior applications are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to compositions for use in hydroseeding, forexample, for hydroseeding landfills. Particularly, the invention relatesto sprayable cover materials for seeding.

BACKGROUND OF THE INVENTION

Hydroseeding is a process used for seeding large areas for vegetationgrowth. Hydroseeding may be used to seed an area in order to growvegetation for soil erosion control, for instance, on sloped surfacessuch as steep hillsides, or to replace lost vegetation after alarge-scale fire. In other instances, landfill caps or othercontaminated sites may be seeded. Grass may be applied by hydroseedingto large areas like golf courses.

Hydroseeding generally is performed by dispersing the hydroseedcomposition, which often includes water, seed and mulch, from a hose ora spray turret of a hydroseeding machine. For large-scale dispersion,tankers or helicopters are utilized.

There are a number of challenges with some currently used hydroseed.Some hydroseed is provided in a hard, brick-like format. This requiresthe user to break up the hydroseed brick prior to use, for instance, byusing a hammer, so that the brick is adequately separated forapplication. Similarly, the hydroseed is prone to separating from water,especially if there is any delay in the use of the product once it ismixed. Current hydroseed products often clog the dispersal equipment,especially the hoses and pumps. Finally, the incorporated grass seedoften tends to float in hydroseed, rather than remaining well dispersed.

Aspects of the present invention overcome these and other limitations ofthe prior art and provide an effective, easily applied hydroseedmaterial.

SUMMARY OF THE INVENTION

The present invention provides an improved hydroseeding material and amethod for applying the hydroseeding material to an area. In one aspect,the invention relates to a hydroseeding substrate. The hydroseedingsubstrate includes 1 part by weight of mulch; and 0.5 to 1.5 parts byweight of a cover composition. The cover composition includes about 50to about 99 weight percent of a bentonite clay and 0.5 to about 25weight percent cellulosic water dispersible polymer or starch. The covercomposition may additionally comprise fiber, colorant, a mixturecontaining lipid essential oil and ethoxylated alkylphenol, syntheticpolymer, soda ash, and/or cement.

In another aspect, the invention relates to a hydroseeding slurry. Thehydroseeding slurry includes a hydroseeding substrate described herein,water, and seed. The hydroseeding slurry may also optionally includefertilizer and one or more soil adjuvants.

In another aspect, the invention relates to a method of forming ahydroseeding slurry. This method includes providing the hydroseedingsubstrate described herein; and mixing the hydroseeding substrate withwater and seed. The method may also optionally include mixing withfertilizer and one or more soil adjuvants.

In another aspect, the invention relates to a method of seeding. Thismethod includes providing the hydroseeding slurry recited herein andspraying the hydroseeding slurry on soil. In some situations, it isadvantageous for the soil to be prepared to better receive thehydroseeding slurry. Soil preparation is well known in the art and willnot be described here.

DETAILED DESCRIPTION OF THE INVENTION

Details of these aspects of the invention, as well as further aspects ofthe invention, will become more readily apparent upon review of thefollowing detailed description and the accompanying claims.

The invention provides compositions and methods for hydroseeding ofsoils, often for areas that are sloped. The hydroseeding substratecomprises, in its simplest form, mulch, bentonite clay, and awater-dispersable polymer and/or starch. The compositions mayadditionally comprise fiber, colorant, a mixture containing lipidessential oil and ethoxylated alkylphenol, synthetic polymer, soda ash,and/or cement.

In one aspect, the invention provides a hydroseeding substrate. Thehydroseeding substrate includes mulch and a cover composition. The covercomposition includes bentonite clay and cellulosic water dispersiblepolymer or starch. In some embodiments, the hydroseeding substrateincludes 1 part by weight of mulch. Any organic material, or mixtures oforganic materials, may be used as mulch. For instance, bark, sawdust,woodchips, seashells, paper products (such as cardboard or newspaper),leaves, vegetation clippings (such as grass), straw, and/or manure maybe used. In certain instances, non-organic materials, such as rubber,plastic, or rock, may be used as mulch. In some embodiments, the mulchis wood mulch.

In some embodiments, the hydroseeding substrate includes 0.5 to 1.5parts by weight of a cover composition. In some embodiments, thehydroseeding substrate includes 0.5 to 1.0 parts by weight of a covercomposition. In some embodiments, the hydroseeding substrate includes1.0 to 1.5 parts by weight of a cover composition. In some embodiments,the hydroseeding substrate includes 0.75 to 1.25 parts by weight of acover composition. In some embodiments, the hydroseeding substrateincludes 0.75 to 1.0 parts by weight of a cover composition. In someembodiments, the hydroseeding substrate includes 1.0 to 1.25 parts byweight of a cover composition. In some embodiments, the hydroseedingsubstrate includes 0.8 to 1.2 parts by weight of a cover composition. Insome embodiments, the hydroseeding substrate includes 0.7 to 1.1 partsby weight of a cover composition. In some embodiments, the hydroseedingsubstrate includes 0.9 to 1.1 parts by weight of a cover composition.

In one embodiment, the cover composition may be a product marketed underthe registered trademark POSI-SHELL by LSC Environmental Products, LLCof Apalachin, N.Y. The cover composition includes bentonite clay, whichprovides a source of both substantivity and bulk. Bentonite clayenhances the smoothness and consistency of the mixture and alsoincreases its tackiness and viscosity, enabling it to better adhere tosoil and cohere to itself. Bentonite is an absorbent aluminiumphyllosilicate, consisting mostly of montmorillonite. There aredifferent types of bentonite, each named after the respective dominantelement, such as potassium (K), sodium (Na), calcium (Ca), and aluminium(Al). For industrial purposes, two main classes of bentonite exist:sodium and calcium bentonites. Many forms of bentonite clay may be usedin the cover composition. The bentonite clay may comprise commercialbentonite clay, for example, Hi-Yield bentonite provided by Wyo-Ben ofBillings, Mont., or its equivalent. In one embodiment, the bentoniteclay may be finely ground bentonite, for example, bentonite provided inthe form of PSM-200™ setting agent provided by Landfill ServiceCorporation. PSM-200 setting agent typically contains finely groundnatural bentonite clay (for example, which can pass through a minus 200sieve); a synthetic polymer, for example, less than 10% syntheticpolymer by weight; pregelatinized wheat starch and soda ash.

In some embodiments, the cover composition includes about 50 to about 99weight percent of a bentonite clay. In other embodiments, the covercomposition includes about 90 to about 99 weight percent of a bentoniteclay. In some embodiments, the bentonite clay is sodium bentonite, orits principal constituent, sodium montmorillonite.

The cover composition includes cellulosic water dispersible polymer orstarch. In some embodiments, the cover composition includes about 0.5 toabout 25 weight percent cellulosic water dispersible polymer or starch.In other embodiments, the cover composition includes about 0.5 to 5weight percent cellulosic water dispersible polymer. Allwater-dispersible cellulosic polymers are envisioned, but those that arecold-water dispersible (i.e. under 40° C.) are preferred. Suitablepolymers include one or more of methylcellulose, ethyl methyl cellulose,hydroxyethyl cellulose (HEC), hydroxypropyl cellulose, hydroxyethylmethyl cellulose, hydroxypropyl methyl cellulose (HPMC), ethylhydroxyethyl cellulose and carboxymethyl cellulose. In certainembodiments, the cellulosic water dispersible polymer is hydroxypropylmethyl cellulose. In other embodiments, the water dispersible polymer orstarch comprises pregelatinized wheat starch. As an adhesive agent inplace of—or in addition to—the cellulosic polymer, one may include wheatstarch, for instance, pregelatinized wheat starch.

In some embodiments, the cover composition additionally includes 0.01 to0.15 parts by weight of fiber. In some embodiments, the covercomposition additionally includes 0.05 to 0.1 parts by weight of fiber.In some embodiments, the cover composition additionally includes 0.05 to0.15 parts by weight of fiber. In some embodiments, the covercomposition additionally includes 0.05 to 0.075 parts by weight offiber. The constituents which may be used as fibers include high densitypolyethylene, polyvinyl chloride, polypropylene, or polyethyleneterephthalate polymer, as well as other types of plastics, shredded intothin hair-like fibers. In some embodiments, the hair-like fibers arebetween one-quarter to one-half inch in length. In some embodiments, thefibers are about one-quarter inch in length. In another aspect, thefiber may be cellulose fibers or synthetic fibers, for example,polyester fibers, such as those included in the formulation “P-100”provided by LSC Environmental Products. Polyethylene terephthalatefibers, such as LSC P-100 fiber, which are manufactured from recycledproducts such as plastic soda containers, have been found suitable. Thepolymer may be a semi-synthetic polymer, for example, a cellulosic waterdispersible polymer, such as hydroxypropyl methyl cellulose (HPMC)treated water dispersible polymer or hydroxyethylcellulose (HEC) treatedwater dispersible polymer. In some aspects, the fibers may be treatedwith organic lubricants as a surface treatment, which allows the fibersto disperse in water. In some aspects, the fibers are 1 denier strands,and further may be pre-stretched and chopped to the desired length. Insome embodiments, the fibers are pre-stretched, 1 denier strands ofpolyethylene terephthalate polymer treated organic lubricants as asurface treatment, chopped to 0.25 inch lengths.

The cover composition may optionally include a colorant. A colorant maybe added to provide the desired opacity or to provide an aestheticallypleasing shade of color to the composition. In one aspect, the colorantmay comprise any conventional coloring agent, for example, a mortar dye;for instance, TRUE-TONE® mortar dye provided by Davis Color Corporationmay be added if desired, though other colorants may be used.

An essential oil may be included in the cover composition in certainapplications, for instance, if a landfill, which may be odiferous, is tobe seeded. An essential oil is a concentrated hydrophobic liquidcontaining volatile aroma compounds from plants. Essential oils are alsoknown as volatile oils and ethereal oils or simply as the “oil of” theplant from which they were extracted, such as oil of clove. An oil is“essential” in the sense that it carries a distinctive scent, oressence, of the plant. Examples of essential oils include orange, lemon,lime, field mint (Mentha arvensis), peppermint, spearmint, wintergreen,menthol, camphor, anise, allspice, clove, almond, vanilla, celery,nutmeg, cassia (Cinnamomum cassia), ginger, sage, buchu (Agathosma sp.),cedarwood, eucalyptus, May chang (Litsea cubeba), sassafras, rosewood,sandalwood, pine, balsam, juniper, tea tree (Melaleuca sp.) andpatchouli. Citrus oils (e.g. orange, lemon, lime) and mint oils (e.g.field mint (Mentha arvensis), peppermint, spearmint, wintergreen,menthol) are readily available, effective and relatively inexpensive,which recommend them for application in the compositions describedherein. In certain embodiments of the compositions of the invention, teatree, eucalyptus and pine oils may be absent.

Ethoxylated alkylphenols are well known in the surfactant and emulsifierart. Two common classes are the nonoxynols and the octoxynols, manyembodiments of which are commercially available from Rhodia/Solvay astheir IGEPAL® series of emulsifiers. The IGEPAL® CO series of nonylphenoxy polyethoxy ethanols are preferred, and octoxynol-9 isparticularly preferred.

A water-conditioning agent, for example soda ash (Na₂CO₃), may also beadded to the compositions described above to improve the efficiency ofthe wetting of the bentonite. This property of soda ash may beparticularly useful when hard water is used as the source of liquid forthe composition. In some embodiments, soda ash may be introduced at, forinstance, 0.5 to 10 weight percent of the bentonite. Other optionalconstituents that can be added to the compositions of the inventioninclude Portland cement, cement kiln dust, fly ash, or stone dust, orany combination of these. In many embodiments, the composition will befree of zeolites, cyclodextrins, urease inhibitors, antimicrobials,borates, boric acid and metal salts other than alkali and alkaline earthmetal salts. By “free of” it is meant that the named constituent issubstantially absent; it may be present in trace, non-functional amountsas an impurity, typically less than 0.1% by weight.

In some embodiments, the hydroseeding substrate includes 1 part byweight of mulch and 0.5 to 1.5 parts by weight of a cover composition,and the cover composition includes about 50 to about 99 weight percentof a bentonite clay and about 0.5 to about 25 weight percent cellulosicwater dispersible polymer or starch. In some embodiments, thehydroseeding substrate includes 1 part by weight of mulch and 0.5 to 1.5parts by weight of a cover composition, and the cover compositionincludes 90 to 99 weight percent of a bentonite clay and 0.5 to 5 weightpercent cellulosic water dispersible polymer. In some embodiments, thehydroseeding substrate includes 1 part by weight of mulch; 0.75 to 1.0parts by weight of a cover composition; and 0.05 to 0.1 parts by weightof fiber. In some embodiments, the mulch in the hydroseeding substrateis wood mulch; and the cover composition includes 90 to 99 weightpercent of sodium montmorillonite; and 0.5 to 5 weight percenthydroxypropyl methyl cellulose; and the fiber is polyethyleneterephthalate polymer.

Mixing of the hydroseeding substrate may be accomplished in anyconvenient fashion. For instance, the hydroseeding substrate can beprepared by mechanically mixing the bentonite and, if not alreadypresent, the water-dispersable polymer. In one aspect the covercomposition (that is, the dry powder) is mixed with the mulch to formthe hydroseeding substrate. The hydroseeding substrate may then beprovided in bulk or packaged in the form of unit packages. While theseunit packages may be of any size, a weight of 50 or 100 pounds may bedesirable.

Table I shows representative examples of the constituents of a 50-poundbag of the hydroseeding substrate. In these examples, the covercomposition is PSM-200™ setting agent provided by Landfill ServiceCorporation:

TABLE I Example No. 1 2 3 Wood Mulch 25 pounds 23.5 pounds 26.5 poundsCover Composition 25 pounds 23.5 pounds 22.0 pounds Fiber  0 pounds   3pounds  1.5 pounds

In some embodiments, the invention relates to a hydroseeding slurry.This slurry contains a hydroseeding substrate described supra, water,seed, and optionally one or more of fertilizer and at least one soiladjuvant. According to aspects of the invention, the water used may beany source of water that is readily available and that would not beharmful to the seed or impermissible due to regulations related togroundwater contamination. As an example, untreated pond water or waterthat contains amounts of contaminants that would make it unsuitable asdrinking water could be used as the source of the liquid.

The amount of water added to the hydroseeding substrate and the seed maybe adjusted to accommodate the soil surface and the vegetation to begrown. For instance, a steeper slope may require the addition of lesswater to the hydroseeding substrate to provide a thicker slurry, whilemore water may be added in those situations where the soil is dryer orwhere the vegetation to be grown requires more liquid. In someembodiments, between 70 gallons and 100 gallons of water are added to 50pounds of hydroseeding substrate. In some embodiments, between 80gallons and 100 gallons of water are added to 50 pounds of hydroseedingsubstrate. In some embodiments, 80 gallons of water are added to 50pounds of hydroseeding substrate.

Soil adjuvants, for purposes of this application, include any additivethat may aid in the growth of the desired vegetation. Such adjuvantsinclude, but are not limited to, additives which may adjust the pH ofthe growing medium (i.e., the soil and/or the hydroseeding substrate orslurry), additional fertilizers, or other nutrients. Additionaladjuvants that may be added to change the viscosity or strength of theslurry, or to improve resistance to rain before cure, include cellulosicpolymers (for example, Xtreme Rain Shield, LSC Environmental Products,LLC, Apalachin, N.Y.) additional fibers, or cement.

In order to facilitate the description of aspects of the presentinvention, the following discussion will primarily refer to the presentinvention as it is applied to hydroseeding grass. It will be apparent tothose of skill in the art that the hydroseeding compositions andapplication process described may also be applied for other vegetation.

According to a further aspect, a method of forming a hydroseeding slurryis provided. This method includes providing the hydroseeding substratedescribed supra. The hydroseeding substrate is mixed with water and seed(and, if desired, other optional components such as fertilizer and/orone or more soil adjuvants) to prepare the hydroseeding slurry. Themethod is accomplished in any convenient fashion. For instance, in oneembodiment, the water and hydroseeding substrate may be mixed first. Themixture may be mixed continuously with a mixing agitator while theingredients are added. If preferred, seed for the desired vegetation,and optionally fertilizer and/or a soil adjuvant, such as a nutrient ora pH adjuster, may be added at this point. In another instance, watermay be added to the hydroseeding substrate, seed, and optionalfertilizer and/or soil adjuvant at the same time.

Typically, the mixture of liquid, hydroseeding substrate, seed, andoptional additional ingredients may be allowed to thicken to form aviscid slurry with the consistency of pudding. The mixing time necessaryto yield a mixture with the proper consistency may vary depending uponthe percentage of each constituent added to the mixture. Once mixed, thecomposition may continue to be agitated, for example, slowly agitated.As an example, a commercial mixing device, such as a Landfill ServiceCorporation PSA 2000 Applicator mixer or its equivalent may be used. Ifthe composition requires transport to the point of application, themixture may be agitated during transport.

As a commercial example, a hydroseeding substrate of the invention maybe brought to a job site. The user mixes the hydroseeding substrate withwater and seed in a hydroseeding machine, in addition to any desiredoptional ingredients discussed herein, such as fertilizer. When themixture is properly agitated, a spray applicator allows the mixture tobe sprayed using a motion similar to spray painting. The resultinghydroseeding slurry is then sprayed on to the desired surface. In someembodiments, the surface is soil. The hydroseeding slurry may be appliedin any thickness, as long as the thickness is sufficient to cover thedesired surface (that is, the soil/landscape) without leaving gaps. Themixture is sprayed in such a manner that a uniform layer approximatelyone-sixteenth to one-half of an inch (1.5 mm to 13 mm) thick exists. Ithas been found that a thickness of one-quarter of an inch often willprovide adequate coverage without wasting material, although thickercoverage may be used.

The hydroseeding slurry disclosed herein is “sticky”, due to thepresence of the bentonite clay in the hydroseeding substrate. Thistexture adds benefits: when grass seed is used with traditionalhydroseed products, which are not sticky, it often will float and willnot remain in suspension. However, the seed will “stick” to the clay ofthe disclosed hydroseeding slurry and remain in suspension, resulting ina more even application of seed. This stickiness also allows thehydroseeding slurry to be applied to vertical and highly sloped surfacesto grow vegetation. In short, the hydroseeding substrate gives themixture better performance properties.

The combination of mulch and the cover composition disclosed hereinovercomes many of the challenges found in prior art hydroseedingmixtures. The disclosed hydroseeding substrate is softer, and thuseasier to separate, than traditional brick-like hydroseed products.Further, traditional hydroseed products tend to harden, while thehydroseeding slurry disclosed herein remains in a more liquid-like form.In some embodiments, the consistency of the hydroseeding slurry is ofpudding. This consistency of the hydroseeding slurry not only preventsthe clogging of hydroseeding machinery and equipment that one finds whenusing traditional hydroseeding products, but even allows the hoses andpumps being used to be lubricated. Further, the reliability of theconsistency of the hydroseeding slurry results in a quicker, easierapplication process.

Although this invention is susceptible to embodiment in many differentforms, certain embodiments of the invention are shown. It should beunderstood, however, that the present disclosure is to be considered asan exemplification of the principles of this invention and is notintended to limit the invention to the embodiments illustrated. Whileseveral aspects of the present invention have been described anddepicted herein, alternative aspects may be effected by those skilled inthe art to accomplish the same objectives. Accordingly, it is intendedby the appended claims to cover all such alternative aspects as fallwithin the true spirit and scope of the invention.

The invention claimed is:
 1. A substrate containing mulch and covercomposition, the substrate being of weight 1.5× to 2.5×, and comprising:(A) mulch at a weight of x; and (B) a cover composition at a weight 0.5×to 1.5×; wherein said cover composition comprises: (a) about 50 to about99 weight percent of a bentonite clay selected from the group consistingof sodium bentonite, calcium bentonite, and combinations thereof; and(b) about 0.5 to about 25 weight percent cellulosic water dispersiblepolymer or pregelatinized wheat starch.
 2. The substrate according toclaim 1, wherein said cover composition comprises: (a) 90 to 99 weightpercent of a bentonite clay selected from the group consisting of sodiumbentonite, calcium bentonite, and combinations thereof; and (b) 0.5 to 5weight percent cellulosic water dispersible polymer.
 3. The substrateaccording to claim 1, wherein the cover composition comprises waterdispersible polymer, and said water dispersible polymer comprises one ormore members selected from the group consisting of methylcellulose,ethyl methyl cellulose, hydroxyethyl cellulose (HEC), hydroxypropylcellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose(HPMC), ethyl hydroxyethyl cellulose and carboxymethyl cellulose.
 4. Thesubstrate according to claim 1, wherein the cover composition comprisespregelatinized wheat starch.
 5. The substrate according to claim 1,wherein the bentonite clay is sodium montmorillonite.
 6. The substrateaccording to claim 1, wherein the mulch is wood mulch.
 7. The substrateaccording to claim 1, wherein the mulch comprises straw.
 8. Thesubstrate according to claim 1, wherein said cover compositioncomprises: (a) about 50 to about 99 weight percent of a bentonite clayselected from the group consisting of sodium bentonite, calciumbentonite, and combinations thereof; (b) about 0.5 to about 25 weightpercent cellulosic water dispersible polymer or pregelatinized wheatstarch; and (c) 0.01 to 0.15 parts by weight of fiber.
 9. The substrateaccording to claim 8 wherein the fiber is polyethylene terephthalatepolymer.
 10. The substrate according to claim 8, comprising: (A) 1 partby weight of mulch; and (B) 0.75 to 1.0 parts by weight of a covercomposition, said cover composition comprising: (a) about 50 to about 99weight percent of a bentonite clay selected from the group consisting ofsodium bentonite, calcium bentonite, and combinations thereof; (b) about0.5 to about 25 weight percent cellulosic water dispersible polymer orpregelatinized wheat starch; and (c) 0.05 to 0.15 parts by weight offiber.
 11. The substrate according to claim 8, wherein: said mulchcomprises wood mulch; and said cover composition comprises: (a) 90 to 99weight percent of sodium montmorillonite; (b) 0.5 to 5 weight percenthydroxypropyl methyl cellulose; and c) 0.01 to 0.15 parts by weight offiber, wherein said fiber comprises polyethylene terephthalate polymer.12. The substrate according to claim 10, wherein: said mulch compriseswood mulch; said cover composition comprises: (a) 90 to 99 weightpercent of sodium montmorillonite; (b) 0.5 to 5 weight percenthydroxypropyl methyl cellulose; and (c) 0.05 to 0.15 parts by weight offiber, wherein said fiber comprises polyethylene terephthalate polymer.13. The substrate according to claim 1, wherein said cover compositioncomprises: (a) about 50 to about 99 weight percent of a bentonite clayselected from the group consisting of sodium bentonite, calciumbentonite, and combinations thereof; and (b) about 0.5 to about 25weight percent cellulosic water dispersible polymer or pregelatinizedwheat starch; and (c) at least one member selected from the groupconsisting of: colorant; a mixture containing at least some lipidessential oil and at least some ethoxylated alkylphenol; syntheticpolymer; soda ash; and cement.